Dredge



aa ECKER I 2,398,?

names I iled Feb. 28, 1941 s Shams-sheet 1 s INVENTOR J 605 tifieckerATTORNEY 5m. 12 1943. G; E BECKER DREDGE Filed Feb. 281, 1941 aSheets-Sheet 2 ATTORNEY v m- 5 4 9 36. asset-(ER pHEDGE Filed Feb. 28,1941 INVENTOVR Gus 1f Hacker ATTORNEY Patented Jan. 12, 1943 r UNETE.STATES P DREDGE Gus E. Becker, Fresno, Calif., assignor of onehalf toHerbert H. Hopkins, San Francisco,

Calif.

3 Claims.

My invention relates to means for recovering values such as gold fromthe earth and is particularly concerned with a dredge adapted forrecovering the values from gravel deposits such as exist in stream beds.

It is an object of my invention to provide a dredge which is very simplein construction and economical to operate to make feasible the workingof deposits of relatively low grade.

Another object of my invention is to provide a dredge which requiresvery little superintendence and maintenance during its operation.

' A further object of my invention is to provide a dredge which can bemade relatively small and can therefore be accommodated to relativelysmall bodies of water.

A further object of my invention is to provide a dredge which isefiective to remove the values from the surrounding material on the bedof a body of water such as a stream.

The foregoing and other objects are attained in the embodiment of theinvention illustrated in the drawings, in which-- Fig. 1 is a plan of adredge constructed in accordance with my invention.

Fig. 2 is a cross-section, the plane of which is indicated by the line22 of Fig. 1.

Fig. 3 is a cross-section on a vertical axial plane through the suctionnozzle and associated mechanism of my dredge.

Fig. 4 is a cross-section, the plane of which is indicated by the line44 of Fig. 3.

Fig. 5 is a cross-section, the plane of which is indicated by the line5-5 of Fig. 3.

In its preferred form the dredge of my invention comprises a hull havinga reentrant portion within which on a frame is disposed a rotatablymounted and vaned perforated suction nozzle secured to a driving shaftdriven from a motor located on the frame. A conduit extends from thesuction nozzle and is joined by a flexible hose to a submerged suctionpump. The frame is movably related to the hull for vertical motion,while the suction pump is driven by an engine disposed on the hull andeffective to furnish all of the operating power and to cause the pump todischarge material sucked from beneath the hull into suitable recoveryapparatus on the hull.

While the dredge of my invention is susceptible to practical embodimentin a number of variant forms so long as the salient characteristics areretained. it has successfully been constructed for use in recoveringgold on relatively shallow streams as disclosed in the accompanyingdrawings. In this instance there is provided a dredge Tall hullgenerally designated 6' which is adapted to float on a body of water Iover the gravel bed 8 within which the values are found, the hullfloating when loaded with a substantially fixed water line 9. The hullis preferably positioned in the customaiy fashion by a spud I l engagingthe material 8 and likewise held in place with respect to the stern ofthe hull 6. The dredge is manipulated by a head line i l which extendsto a winch drum 12 arranged on the hull for convenient manual operation.Also, there are provided a port side line i3 extending to a hand winch Mmounted on the hull 8 and a starboard side line 16, which extends to ahand winch I1 located on the opposite side of the hull. By suitablemanipulation of the-head line, the side lines and the spud, the dredgeis variously positioned over the bed 8;

The hull ii is generally rectangular in plan, but the bow has areentrant portion 18 in at least the forward parts thereof, or ifdesired, the hull can be constituted by a pair of pontoons as shown, therearward portions of which, however, are bridged 'at various points.feature is to have a clear reentrant portion in the forepart of thehull. Rising from the hull there is a stationary framework generallydesignated l8 and which is conveniently fabricated of tubes weldedtogether. Adjacent the hull center,

' the framework and the hull form supports for a lower pair of links 2iand an upper pair of links 22, which are mounted to pivot about axes 23and 24 respectively. The outer ends of the links are connected by pivots26 and 21 to a frame 28. The lower pair of links 2| are spanned by crosstubes 29 at appropriate intervals while the upper pair of links 22 arespanned by brace tubes 31 at appropriate locations. This arrangementforms a parallel link motion for affording a substantially verticalmovement of theframe 28 with respect to the barge or hull 6.

In order to raise and lower the frame 28, the hull 6 over the reentrantportion is bridged by a superstructure 32 connected with or forming partof the framework 19 and provided with appropriate braces 33. From thesuperstructure 32 is suspended a pulley 34 to which a cable 36 is deadended. This cable extends around a pulley 31 secured to a brace 3| ofthe links 22 and then extends around the pulley 34 and to a winch 38mounted on the framework 19. The winch is driven through a gearreduction 39'by an electric motor 4| or other suitable source of power.When the motor 4| is energized in forward or reverse direction the cable36 is correspondingly The desirable taken in or paid out so that theframework 28 is raised or is permitted to lower under its own weight. Toaugment the weight of the frame 28 and to increase the lowering force,we preferably mount a ballast tank 42 on the links 2| and 22 and fillthe tank with an amount of water to give the appropriate weight to thestructure. With the arrangement as so far described there is provided awell braced and easily maneuverable structure by means of which a frame28 can readily be raised and lowered substantially vertically andadjacent the forward part of the bow of the barge or hull 6.

In accordance with my invention the frame 28 is secured to a suctionconduit 46 (Fig. 3) preferably by welding the individual members of theframe 28 to the circular-cylindrical body portion of the conduit.Adjacent the lower end of the conduit 46 there is provided what ineffect is a continuation thereof constituted by a circularcylindrical,hollow nozzle 41, which for the most part is coaxial with the conduit;46 and adjacent its lower end gradually diminishes in diameter andconverges substantially parabolically in cross-section to form a closedlower end 48. Around the exterior of the nozzle so formed, I provide aflange 49 which is preferably a flat strap of metal wrapped spirallyaround the surface of the nozzle and securely welded thereto. Extendingspirally around the nozzle between successive flights of the flange 49is a series of perforations affording access to the interior of thehollow nozzle from the exterior thereof.

The nozzle 41 is intended to be rotated and for that reason on itsinterior is provided a spider 52 (Fig. 5) which is conveniently weldedinplace and is designed to receive a central, coaxial drive shaft 53which extends upwardly through the conduit 46. The junction between therotatable nozzle 41 and the conduit 46 is preferably bridged and sealedby a circumferential rubber collar 54 secured in place by a clamp 55pinching around the conduit 46. Since the structure operates wet orunder water for most of the time, the friction between the nozzle 41 andthe sealing band 54 is very slight, yet due to the reducedpressurewithin the nozzle and within the conduit 46, the rubber band 54 providesa thoroughly satisfactory and long wearing seal.

The drive shaft 53 passes through a stuffing gland 56 at the upperelbowed end 51 of the conduit 46 and traverses the height of the frame28. The upper end of the drive shaft emerges through a bearing in thetop of the frame 28 and receives a driven sprocket 59 engaged by a chain6| which is also trained around a sprocket 62. A gear reduction 63 and amotor 64, mounted on the frame 28, drive the sprocket 62 so that throughthe drive shaft 53 the suction nozzle 41 is appropriately rotated.

Material excavated by the nozzle and passing into the interior thereofand through the conduit 46 leaves the conduit through the dischargeelbow 51 and passes into a flexible suction hose 66 clamped to thedischarge elbow 61 and in part supported by a clip 68 on one of thecross-bars 28. The suction hose 66 is extended and clamped to the inlet69 of a suction pump 1| supported by a bracket 12 from the hull 6, butdisposed below the water line 9. Since the entire suction line can beimmersed, diiiculty with respect to air leaking into the line or withpriming of the pump is obviated.

The pump 1| is operated by a drive shaft 13 which extends to a universaljoint I4 located at one end of a source of power 16 such as a completeautomotive engine power plant, mounted on bridges 11 spanning the sternof the hull 6.

Material discharged by the suction pump H flows through an upstandingdischarge pipeline 18 to a distribution box 19 resting on the upperportion of the framework l9. Within the box 19 the force of thedischarge is broken and the flow is diverted into the upstream ends ofsluices 8| separated by a division plate 82. The sluices are arranged onthe framework I9 and are provided with suitable recovery apparatususually including riflles 83 so that the liquid and waste material isdischarged over the stern of the hull, whereas th values are retained bythe rifiies.

In order to supply power to operate the motor 4| when desired and moreespecially to supply power for the motor 64 which usually operatescontinuously with the operation of the pump 1|, the engine 16 isequipped with a pulley 86 driving a belt 81 entrained around a pulley 88of an electric generator 89 suitably mounted on the hull 6 and connectedby appropriate circuits (not shown) to the various electricalinstrumentalities on the dredge.

In the operation of this structure the various winches are utilized tooperate the head line and the side lines to position the drege in aselected location wherein the spud II is utilized as a fixed point. Theengine 16 is started so that the pump 1| is put into operation to drawmaterials through the perforations 5|, through the hollow nozzle 41, theconduit 46 and through the flexible suction hose 66 into the pump andthence outwardly through the discharge duct 18, the distribution box 19and then over the riflles 83 in the sluices 82- finally to dischargeover the stern. The generator 89 is also started at the same time andelectricity is thereby supplied to the motor 64 so that the suctionnozzle 41 is rotated by operation of the chain 6| and the drive shaft53.

When the suction nozzle is in an appropriate location with respect tothe gravel bed 8, the motor 4| is operated to pay out cable 36 from thewinch 88, so that due to its own weight and action and due to theadditional weight of the contents of the tank 42, the suction nozzlebores its way into the earth 8 beneath the water. The nozzle thereuponexcavates a crater in the gravel, but the intermixed fine material,including the values, is sucked into and through the apertures 5| to bedeposited eventually behind the riflles in the sluices. The suctionnozzle 41 is from time to time raised and lowered and is moved forwardand aft and from side to side by operation of the head and side lines ofthe dredge until finally all of the material 8 on the bed of the streamhas been worked.

I claim:

1. A dredge comprising a hull having a forward reentrant portion, anupright frame disposed forward of said portion, a suction conduit onsaid frame, parallel links pivotally connected to said hull and to saidframe, a suction nozzle rotatably mounted on said conduit, a suctionpump on said hull, a flexible hose for connecting said conduit to saidpump, and means on said hull for raising and lowering said frame.

2. A dredge comprising a hull having a forward reentrant portion, anupright frame disposed forward of said portion, parallel links pivotallyconnected to said hull and to said frame, a superstructure on said hullextending over said reentrant portion, means connected to saidsuperstructure for raising and lowering said frame, a suction nozzle onsaid frame, a suction pump on said hull, and a flexible hose connectingsaid suction pump and said nozzle.

3. A dredge comprising a hull having a forward reentrant portion, asuperstructure on said hull and extending over said reentrant portion,an upright frame adapted to rise and fall with respect to said hull andforwardly of said reentrant portion, superposed parallel links pivotedat one end to said superstructure and at the 10 pump.

GUS E. BECKER.

